Obstructive vs. Restrictive Lung Diseases

Question 1

What is the definition of an OBSTRUCTIVE airway disease?

Answer 1

Increased resistance to airflow secondary to obstruction of airways

Lung does not empty

Air is trapped

Problem with ability to empty lung

Question 2

Give four examples of OBSTRUCTIVE diseases

Answer 2

Asthma
Chronic Bronchitis
Emphysema
Bronchiectasis

Question 3

Explain the results of pulmonary function tests indicating an OBSTRUCTIVE disease

Answer 3

↓ FEV1/FVC ratio DECREASED below 80%

↓↓FEV1
↓FVC
↓Peak flow

↑FRC
↑RV
↑TLC
(FRiCkin RV needs some increased TLC but it’s hard with COPD!)

V/Q mismatch

Question 4

In OBSTRUCTIVE diseases, what happens to the blood vessels and what does that lead to?

Answer 4

Chronic, hypoxic pulmonary vasoconstriction can lead to cor pulmonale (enlargement of R side of heart)

Question 5

What is the definition of a RESTRICTIVE airway disease?

Answer 5

Decreased lung volume and capacity

Problem with ability to fill the lung

Question 6

Explain the results of pulmonary function tests indicating a RESTRICTIVE disease

Answer 6

↑FEV1/FVC ratio INCREASED above 80%

↓FEV1
↓↓FVC
↓Peak flow
↓FRC
↓RV
↓TLC
Everything decreased except ratio

Question 7

An example of a RESTRICTIVE disease is interstitial/infiltrative diseases, explain the pathogenesis with examples

Answer 7

Interstitial diseases cause fibrosis of interstitium

the interstitium is the wall of alveolar sacs which is thin and delicate allowing for efficient gas exchange

The walls fibrose around the alveoli, causing difficulty in lung expansion

Examples:
ARDs
Pneumoconiosis
Pulmonary fibrosis

Question 8

An example of a RESTRICTIVE disease is chest wall disorders, explain the pathogenesis with examples

Answer 8

If the patient is obese, when they fill up their lungs they have to fight the force of the chest wall to open lung completely

Force on chest wall prohibits lung to open fully and fill resulting in restrictive disease.

Examples:
Obesity
Kyphoscoliosis
Polio

Question 9

What kind of breaths would a patient exhibit in a RESTRICTIVE disease?

Answer 9

Short and shallow breaths

Question 10

What ‘poor muscular effort’ diseases increase the risk of developing a RESTRICTIVE disease?

Answer 10

Polio

Myasthenia Gravis

Guillain-Barre Syndrome

They are often associated with weakened muscles, damaged nerves, or the stiffening of the chest wall tissues

Question 11

What ‘ poor structural apparatus’ diseases increase the risk of developing a RESTRICTIVE disease?

Answer 11

Scoliosis

Morbid Obesity

Question 12

How does COPD look on a CXR?

Answer 12

Hyperinflated lungs

Flattened diaphragm

Air pockets (bullae)

Question 13

List all the RESTRICTIVE diseases, separated via affecting the upper and lower lobes

Answer 13

UPPER LOBES: (CHARTS)
C - oal Workers Pneumoconiosis
H - ypersensitivity Pneumonitis/Histiocytosis
A - nkylosing spondylitis
R - adiation 
T - uberculosis 
S - ilicosis/Sarcoidosis 

LOWER LOBES: (ACID)
A - sbestosis
C - onnective tissue disorders (i.e SLE + Rheum Arth)
I - diopathic pulmonary fibrosis
D - rug induced